


Late Bloomer

by kaythulu



Category: South Park
Genre: Alpha Stan Marsh, Alpha/Beta/Omega Dynamics, Anal Sex, M/M, Mutual Pining, Oh they are both 18, Omega Kyle Broflovski, Rimming, they are so in love it hurts
Language: English
Status: Completed
Published: 2020-12-23
Updated: 2020-12-23
Packaged: 2021-03-10 23:41:29
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,665
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28255590
Author URL: https://archiveofourown.org/users/kaythulu/pseuds/kaythulu
Summary: Kyle always feared he would present as an omega and senior year of high school, his nightmare comes true.Thankfully, his alpha best friend is there for him.
Relationships: Kyle Broflovski/Stan Marsh
Comments: 5
Kudos: 113





	Late Bloomer

**Author's Note:**

> It took me 2 weeks to write this and I'm honestly happy with how it came out! Enjoy!

Kyle had figured out from an early age that he was not going to present as an alpha.

For starters, male alphas typically presented in their early teens. By the time sophomore year came around, Stan and Kenny had both presented as alphas. Meanwhile, Kyle had just turned 18 and had yet to present.

Stan being an alpha was no surprise. Despite having an affinity for music more than sports, Stan was still a superstar athlete at South Park. When sophomore year came around, Stan wasn’t built like the stereotypical alphas on TV but he was still tall, being well over 6’0. Kenny was more of a surprise, since everyone (including him) expected him to just be a beta like the majority of their class. 

Kyle knew he had no chance of being an alpha- he wasn’t short, but he was average in height, especially compared to the other guys in class. He wasn’t muscular or tall like the other male alphas in class, which currently going on senior year was a total of Stan, Kenny, Craig and Token. 

Kyle always expected he would present as a beta, but two events occurred that caused self-doubt and worry about his status.

The first was Butters presenting as an omega late sophomore year. This wasn’t a surprise- he was easily the smallest boy in the class. But one of his childhood friends being an omega caused a stir in their class. In modern society, male omegas weren’t uncommon but were still highly sought after by alphas compared to the more common female omegas, since fucking them felt just as good without the added risk of pregnancy. 

Kyle and the rest of the class were genuinely worried about Butters, scared that one day a much older and stronger alpha would break into his room and claim him, or at least take advantage of Butter’s innocence and trust in others. Laws were still heavily in favor of alphas, even if they claimed and bonded with an omega without their explicit permission. The thought of Butters one day being forced to live with an older, and possibly abusive, alpha against his will made Kyle’s stomach turn.

It was a huge relief to Kyle and everyone else when Butters and Kenny walked into first period together, Butters with a claiming mark on his neck and Kenny’s scent all over him. Kyle could tell Butters wasn’t happy being an omega, but Butters clearly was happy to be Kenny’s mate and Kyle was just glad his close friend didn’t meet the awful fate that many young male omegas do.

The real shock came when Tweek presented as an omega the next year. Tweek and Kyle often laughed together about how they were “late bloomers,” confused as to why they had yet to present as betas like most of the other guys in class. Tweek and Kyle were roughly the same height as all the other betas and the two were just playing the waiting game at that point to get the confirmation.

When Tweek and Craig failed to show up to school for two weeks, the school began to gossip, wondering if something awful had happened to them. Kyle was standing at his locker before the start of 5th period when Stan walked over to him, face pale and eyes wide as he told Kyle the news:

Tweek had gone into heat while he was alone at home. The heat had made him so delirious he couldn’t contact anyone and was stuck alone in his room for hours. When Craig showed up to check on his boyfriend, he had barely managed to stop an older alpha male from breaking into the Tweak house, drawn by the scent of an unclaimed male omega in heat. Craig was able to fight the older alpha male, but was severely injured in the process. Tweek was in such a state of shock, both from the sudden heat and his boyfriend nearly dying trying to protect him, he was near catatonic and was admitted into the hospital as well. 

After Stan told him about the incident, Kyle had to excuse himself to the bathroom. Locking the door behind him, his knees finally gave out and the urge to throw up became too strong to fight. A sobbing mess, Kyle hugged his knees to his chest. Hearing what had happened with Tweek, he knew.

He knew he was going to present as an omega, it was just a matter of when. 

A few months have passed since then- Tweek and Craig returned to school about a month after the incident, Craig sporting a scar on his face from his fight with the older alpha and Tweek with Craig’s claiming bite on his neck. It was summertime in South Park, and everyone in class was buzzing with excitement that they only had one year left of high school.

Well, Kyle would be excited if it weren’t for the impending sense of doom he felt every day he didn’t present as a beta. Everyone in his life assured him he was just a late bloomer. Some beta males don’t even present until their college years, his parents were always telling him. And he supposed it was possible, but as usual, his anxiety got the better of him. 

He felt sick every time he thought about it. Struck with nightmares where he was home alone, no one around when his first heat started. He had no idea what being in heat actually was like, but he could guess. He knew the first heat was the worst, with some omegas even dying of a heat stroke from how bad it can get. Kyle had heard stories of omegas being so desperate that they let anyone claim, not caring about the consequences of being forever bonded with a stranger, becoming no more than a sex toy- forever owned by alpha they didn’t want.

There was only one person Kyle was interested in bonding with and that was Stan. Ever since Stan had presented as an alpha, his feelings towards his best friend became not so platonic. He began noticing things about Stan he hadn’t noticed before, specifically how much bigger he was compared to the red head. Kyle found himself staring at Stan during class, his large hands twiddling with a pencil while Mr. Garrison was going off on some irrelevant tangent. His hands were large compared to his own. Kyle bet he could wrap both his wrists in one of his hands and pin him against a wall.

His demeanor also changed, though Stan tried to pretend he was the same guy before presenting as an alpha, being more confident in his stride and speech. The few alphas that had bothered Kyle were stopped by Stan, who angrily threatened them to “leave his best friend alone.” The way his nostrils flared in anger, his voice both terrifying and protective at the same time, his scent becoming stronger and… _dominant_ it flooded Kyle’s senses with pure _want._ Stan turned to Kyle, his eyes gentler and scent so musky it made Kyle’s knees tremble. When Stan asked if Kyle was alright, it took every ounce of self-control to not drop to his knees right there and rub his face against Stan’s clothed crotch.

In retrospect, his intense attraction to his alpha best friend should have been his first clue that he was an omega.

His attraction to an alpha led to conflicted feelings. On one hand, male alphas were looked down upon compared to females. Unlike female omegas, male omegas couldn’t get pregnant. Male omegas were labeled as “fuck toys,” having no other purpose than to be holes for alphas. Butters and Tweek had already experienced harassment from other alphas in school, though they usually were shut down by Kenny and Craig. He knew his life was going to be harder by being an omega. But if he was an omega, he had a chance to actually be with his alpha best friend- an alpha who would protect him, take care of him and love him unconditionally. 

Though that definitely depended on how the alpha actually felt about Kyle.

Stan… He truly was the perfect alpha. Puberty had been overly kind to Stan Marsh. He was so tall, nearly towering over Kyle when the two stood next to each other. He was handsome, with a boyish face that made everyone who met him for the first time swoon. Kyle was positive Stan had a laundry list of omegas and betas who wanted to get into his pants, but Stan never really seemed interested in relationships, His last relationship was with Wendy, which ended back in middle school when Wendy had presented as an alpha- a fact that still shook South Park today, with her being the only female alpha in the entire school. 

Halfway through the summer when his parents asked if Kyle wanted to go on a last minute vacation to California. Kyle refused, both from disinterest in spending his last summer before college with his family and fear of starting his heat thousands of miles away. Kyle’s parents still were under the belief that Kyle was a beta, and Kyle was too afraid to express his concerns.

It was mid-afternoon and Kyle was lounging in his bed, the fan on full blast as he read a book that Butters had lent him. Kyle didn’t leave the house much, panicked at the thought of going into a first heat out in public. He didn’t look at his phone much either, trying to ignore the texts from Stan about getting together for video games.

Kyle’s eyes were hardly focusing on the letters on the page when he suddenly felt his shorts become wet. Had he spilled water somewhere earlier and not realized? Putting the book to the side, he shifted up on his elbows to get a closer look at the bed sheets.

And then the first wave of heat hit him. 

Kyle hunched over with a loud gasp, sensations bursting through his body so fast he almost couldn’t process what exactly was happening. The first horrifying realization was the wet spot wasn’t water spilled on his bed sheets, but rather the wetness was coming from him. The distinct feeling of slick forming inside him was maddening, the entire room felt hot. No, it wasn’t the room, it was Kyle who felt hot, body already starting to sweat, breathing became heavier. 

It was here. Kyle was right. He was an omega, and his first heat was here.

* * *

Stan checked his phone again, for at least the hundredth time in the past hour. He was used to Kyle declining his requests to hang out, but he wasn’t used to Kyle just ignoring his texts. The flashing screen in front of him showed his outgoing message, _Hey dude, wanna come over and play some COD?_ It wasn’t that Kyle hadn’t responded, but hours later and the red-haired boy had yet to even read the message. Stan reasoned to himself- Kyle was just busy with something, nothing was wrong with his best friend and he was totally okay.

Stan couldn’t shake this feeling that something was up. Maybe he was overthinking it, hell, he was sure he was overthinking things. But all his senses were screaming at him that he needed help- that Kyle was in trouble and needed Stan to protect him. Stan wanted to slap himself from how ridiculous he felt, pacing the floor of his living room. He shouldn’t be feeling like this. Kyle wasn’t an omega, let alone Stan’s omega. 

Though it wasn’t like Stan hadn’t _thought_ about it. He knew it was wrong to hope that your best friend would present as an omega. Shortly after presenting as an alpha, he was plagued with thoughts of Kyle in heat, desperate for Stan and his alpha cock. He would give Kyle what he needed and then sink his teeth into the meat of this throat, claiming Kyle as his for the rest of their lives. 

Stan desperately kept this to himself, but his protective nature of the red-haired boy still came out, trying to pass it off as being a caring best friend, but he knew these protective urges came from his alpha side. 

Well, it couldn’t hurt to check on his friend, right? He walked over to his best friend’s house, knocking on the door a couple times. When there was no answer, he debated giving up, chalking it up to Kyle not being home. But his instincts yelled at him to go inside, and without realizing he got the extra house key from the mat and charged in.

The moment he was in the Broflovski house, he nearly doubled over from how strong the scent inside was. It was a scent he never personally experienced, but it was a scent his alpha nature was finely tuned to hunt down.

An omega in heat.

Not just any omega. Among the scent of desperate and feral lust of an omega in heat, there was an underlying familiar sweetness that Stan had grown to love- it was Kyle in heat.

His legs moved on their own, practically sprinting up the stairs and throwing open the door to Kyle’s room. 

“Holy fuck, Kyle-” 

Stan was already half-hard upon entering the house, lured by the smell of an awaiting omega, but he was now throbbing at the sight before him.

Kyle was naked from the waist down, t-shirt practically see-through from how much he was sweating. His cock lay heavy on his stomach, pre-cum dripping from the tip. His breath was heavy, face burning and giving off a sweet scent so strong it made Stan want to pounce on the red-haired boy right there and then.

There was a heavy silence in the room as both boys tried to process what was happening. 

Kyle wanted to die of embarrassment, body burning with shame and arousal at Stan walking in and seeing him this desperate for an alpha. His heat before was just bearable, but now that an available alpha was in close proximity... his musky scent so overpowering it was driving him insane. His hole feeling even more empty now that what he needed was right in front of him.

“Kyle..” Stan uttered again, this time the tone of his voice was gentle but also firm and so _alpha_ it made Kyle squirm against the sheets. 

“St-Stan? What are you doing here?” Kyle squeaked out, unsure what to say or do. He felt like clawing at his own skin from Stan’s scent- he had heard the phrase “smelled like an alpha” on TV before, but fiction was nothing like experiencing the overpowering scent first-hand. Kyle was unable to tear his eyes away from his obvious hard cock in his jeans. He wondered what it would look like- what it would feel like inside him, finally claiming Kyle as his. 

Stan gulped loudly, shifting on his feet in a desperate attempt for friction against his straining erection, “I- uh, came to check on you? You hadn’t read my text messages, so I was, just, y’know, worried..” 

Kyle laughed pathetically, “Well, I’m kinda busy right now, dude.” He snarked back, but Stan could tell his presence was affecting Kyle, the omega breathing even harder and the sweetness of his slick permeating all of Stan’s senses. 

“Y-yeah, I can see that.” Stan mumbled quietly, almost to himself, “I’m sorry for just barging in, I just-”

“Couldn’t resist the smell of an omega in heat?’ Kyle barked back, his tone shifting from awkward embarrassment to anger and humiliation. Stan’s eyes widened at Kyle’s accusation, “W-what, no!” Stan yelled back, unconvincingly, “Okay, maybe I did, but-”

“I knew it…” Kyle said miserably, pulling his soaked blanket over himself. “You hate me now, don’t you? I’m disgusting.” 

Stan grabbed on to his own arm, desperately stopping himself from pulling Kyle into his arms to comfort the shaking omega. It hurt. It hurt like hell to be an alpha in the presence of a needy omega, having what he needs but not being able to give it to him.

“Kyle, what the hell are you talking about?” Stan practically yelled at the red-haired omega, who was now clutching his bedsheets with shaking hands, “I would never find you disgusting, why the fuck would you even think that, dude?”

Kyle bit the inside of his cheek, tears welling in his green eyes, “Because, dude! I’m an omega! I-I’m nothing- nothing more than a fucktoy.” 

Stan finally broke, walking over to his best friend who was now clutching his blanket so hard his knuckles were turning white, teary eyes downcast in shame. He didn’t wrap Kyle in his arms like he wanted, scared being so close to Kyle’s neck will shatter his self-control, but placed his large palm comfortingly on the red-head’s shoulder.

Kyle’s breath hitched at the sudden contact, Stan rubbing soothing circles into his shoulder as he spoke slowly, “Kyle, I would never find you disgusting. And I don’t care that you’re, y’know, an omega. You’re still the same Kyle, this doesn’t change anything-”

Kyle tore away from Stan’s touch, violently turning his body around and throwing the blanket away from him, eyes black from arousal and anger. 

“Doesn’t _change_ anything? Cut the shit, Stan. You _know_ this changes everything. I mean- you’re an alpha! Don’t you- god, don’t you realize what this means? Alphas and omegas aren’t supposed to be friends! Our friendship is basically fucked and it’s all my fault.” He cried out the last few words, still trying to keep it together. He was devastated at the thought of losing his best friend, but was also still extremely turned on by the alpha’s . Kyle couldn’t decide if he wanted Stan to leave him alone or fuck him into the mattress. 

Well, he knew what he wanted Stan to do, but he wasn’t about to say it out loud. He couldn’t take advantage of his omega heat and Stan’s hormones to get what he wanted, refused to be selfish about this.

Stan, however, laughed in disbelief at what Kyle was saying, “Well,” Stan braced himself for his next words, “What… what if I said I didn’t want us to be friends?”

Kyle stayed silent, so Stan continued, “I don’t want us to be friends, Kyle. I want us- fuck, I want us to be bonded.” 

Kyle gasped, blood roaring in his ears and heart beating so fast he thought it would stop any moment. 

“You’re-you’re just saying that because I’m in heat.” Kyle accused, voice weak. Stan scoffed in frustration, “Dude, I’ve been in love with you since I was, like, 13. I’ve always wanted to bond with you, Kyle. I want to be with you and I am so fucking happy I get to be your alpha- if you feel the same way...” He quickly added, face burning and cock still painfully hard in his jeans.

Tears fell from Kyle’s eyes, but this time from pure joy. He gave Stan a shy smile, “Idiot. I would have wanted you even if I was an alpha.” 

Stan’s heart jumped out of his chest from Kyle accepting his confession. At long last, he leaned down, pausing when his lips were barely touching the red-head’s lips, the two breathing each other’s air. Kyle felt dizzy, giving Stan a small nod, eyes pleading with the alpha to _please touch me, I need it so badly._

With that, Stan crushed their lips together, the two moaning when their lips finally met. Stan held Kyle’s face in both his hands, getting on his knees on the bed in front of Kyle. As Stan sucked Kyle’s bottom lip into his mouth, Kyle let out another loud moan, opening his lips to let the alpha explore his mouth.

He melted in Stan’s arms, momentarily forgetting his heat and just letting himself enjoy finally kissing the boy he has been in love with for years. Kyle could count the number of people he kissed on one hand, and none of them really could be counted as a “kiss.” But now, being held in an alpha’s strong arms, his mouth being thoroughly worked over by Stan’s tongue, he finally knew what it meant to be kissed. 

The heated kiss grew desperate, Kyle’s body catching up with his head, and he broke off the kiss to moan into Stan’s ear, “I _need_ you, Stan. Please-” Stan groaned against Kyle’s neck as he nipped small kisses on his skin. 

“I got you, baby.” Stan says hungrily, before roughly pushing Kyle onto his back, pinning the smaller boy with his own body on the mattress. He gave Kyle one last heated kiss, trailing kisses down his jawline and neck. Kissing down his body, he stopped at one of Kyle’s sensitive nipples, sucking it into his mouth. Kyle keened loudly, head lolling back and forth on the pillow. 

“Take your shirt off.” Stan commanded, and Kyle quickly obeyed, stripping the now soaked garment off and tossing it on the floor.

“Spread your legs for me, babe.” Stan huskily said. Kyle shivered from the possessiveness in Stan’s voice, eager to obey his alpha. Hooking his hands under his knees, he spread himself, showing Stan what was his. His ass leaking slick, Stan takes a moment to drink in the sight of _his_ omega, body flushed bright red, eyes glassy with pleasure, hole clenching at the attention Stan is giving him.

Stan eyes the omega hole that is dripping slick and gives in to his desire to know Kyle fully, tongue peeking out to lick at the entrance. Kyle yelps in surprise, fingers clawing at the bed sheets as Stan laps at his hole, the alpha moaning as he sticks his tongue inside. “Stan, stop, that’s gross-” Kyle rasps, breath coming out in small hiccups. 

Stan moans again, “Not gross, you taste so sweet, Kyle, _fuck.”_ He gives Kyle a few more licks, Kyle jerking on the bed with each thrust of his tongue. Stan breaks his tongue away from Kyle’s ass, replacing it with his pointer finger. 

“God.. you’re so wet.” Stan mumbles, mostly to himself, “Look at this puffy omega hole, you’re really desperate for it, aren’t you?” Stan’s voice oozes of sex, the husky tone of it driving Kyle absolutely insane. 

“Yes…” Kyle whimpers, crying out as Stan slides two of his fingers in, feeling how warm and _wet_ he is. It feels good, heavenly even, having Stan touch him like this. Stan works him open with his fingers, sliding in a third with ease. It’s so good but it isn’t enough.

“Yes…” Kyle whimpered, crying out as Stan slides two of his fingers in, feeling how warm and _wet_ he is. It feels good, heavenly even, having Stan touch him like this. Stan works him open with his fingers, sliding in a third with ease. It’s so good but it isn’t enough. 

“God, I didn’t know someone could get this wet,” Stan cooes, “So wet and ready for my cock.” Kyle nods frantically, not even sure if Stan was asking a question but the answer was _yes he was ready for Stan’s cock, needed it like he needed air._

“Stan, stop, please…” Kyle breathes desperately, and Stan pulls his fingers out. He worries that he might have crossed a line with the dirty talk, taking his fingers out, Kyle whining loudly at the loss. He feels so empty, hips grinding on their own trying to force Stan’s fingers back in. 

“Shit, Kyle, did I go too far?” Stan frantically asks, heart sinking at the thought of hurting his omega.

“No, you didn’t. But I need you, Stan.” Kyle’s voice trembles out, “Take me. Make me yours.” 

Stan growls, alpha instinct overtaking his body, getting off the bed to shed his jeans and underwear off before pinning Kyle back on the bed, Kyle letting out a surprised squeak as Stan crawls on top of him.

He leans in to nuzzle Kyle’s neck, breathing in his intoxicatingly sweet scent, pushing Kyle’s hips up as he lines his hard cock up to the omega’s leaking entrance. Kyle instinctively wraps his legs around Stan’s back, head rolling back when he felt the cock head finally push in. 

“I’m going to fuck you so hard,” Stan whispers right into Kyle’s ear, “God, I can’t fucking believe you’re finally all mine.” 

“Yes!” Kyle screams, nails digging into Stan’s back as Stan pushes into him. Kyle had assumed it would hurt, but he is so wet that there is no resistance. The feeling of Stan’s cock pressing into him is everything he needed and more, he feels light-headed, shameless noises of pleasure escaping his lips. When Stan is fully seated inside the omega, Kyle is already a moaning mess, drowning in the white hot pleasure that was Stan’s alpha cock inside him.

“That’s it.” Stan says, still nuzzling Kyle’s neck, “That’s what you needed, wasn’t it?” 

Kyle nods in response, unable to speak coherently at this point. Stan pulls his hips back slightly and pushes back in, a strangled noise coming out of Kyle as Stan starts to fuck into him. 

Stan’s thrusts turn rough, shifting onto his palms so he can fuck into Kyle harder. Kyle drowns in pleasure, screaming every time Stan roughly hits his prostate, cock leaking pre-come like a faucet. Stan's eyes are black, searing into Kyle’s own as he shows Kyle how an omega is supposed to feel in heat, as he is claimed, completely surrounding himself to his alpha. 

Kyle knows he is about to come, and can feel it coiling in his belly as Stan’s moans turn into predatory growls, head leaning back down to Kyle’s neck, right above his pulse point, thrusts losing their rhythm as his climax approaches.

Even in their frenzy fucking, Kyle manages to get a few words out, “Stan, c-claim, _ah,_ claim me, please,” tilting his head back to allow Stan easier access to his neck. 

He is close to coming, and as Stan finally unleashes into Kyle, he latches his teeth onto his neck, and Kyle sees white. Eyes rolling back as he yells Stan’s name in pure ecstasy, both from his orgasm and the feeling of Stan’s teeth sinking into his skin, forever marking Kyle as Stan’s omega. 

For a few seconds, there is nothing but the sound of their breathing as they calm down from their highs. Kyle had heard the act of being claimed was overwhelming, and he felt fuzzy, like his head was still trying to process what Stan had done to his body. 

Stan pulls out, Kyle whining both from the loss and the strange feeling of Stan’s cum leaking out of him. He wraps Kyle in his arms and pulls him to lie against his chest, kissing the slightly bleeding mark that is now forever branded on Kyle’s neck.

“Does it hurt?” He whispers tenderly, and Kyle giggles from how gentle and caring Stan was acting, a complete 180 from his aggressive nature just minutes ago. 

“A little,” Kyle answers honestly, “But honestly, the pain is nothing. I’m just- I’m so happy, I could die.” 

Stan holds on to Kyle tighter, and Kyle raises his eyebrow at the alpha, “Sorry, like- I know you were joking just now but I feel… really protective of you.” Kyle hums satisfied, laying back down on Stan’s chest.

“I love you, Kyle.” Stan murmurs in Kyle’s ear, placing a kiss on his forehead. Kyle makes a satisfied noise of contentment, nuzzling into Stan’s chest, “I love you too,  _ my alpha.”  _ Stan chuckles, but Kyle can feel his hard beating just a tad faster. 

He knows the heat will come back eventually, but for now, he lets his eyes slip shut, Stan playing with the hairs on the back of his neck. Kyle lets himself fall into a deep, peaceful sleep, knowing that Stan will be there to take care of him whenever he wakes up.

**Author's Note:**

> Thanks for reading!  
> I'm considering writing side fics for Bunny and Creek in this AU, let me know if you would be interested!


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